The White House described a false inbound missile alert received by Hawaii residents on Saturday morning as an "emergency management exercise," offering no further explanation for the erroneous warning.

"The President has been briefed on the state of Hawaii's emergency management exercise," White House deputy press secretary Lindsay Walters told reporters in West Palm Beach, Fla.

Hawaiians awoke to alerts on their mobile devices and televisions around 8 a.m. local time Saturday, warning of an "inbound" ballistic missile threat.

This is not a drill," the emergency alert stated.

Trump was visiting his golf course in West Palm Beach, Fla. at the time of the incident Saturday.